Method and apparatus for applying a film adhesive to a perforated panel

ABSTRACT

A method and apparatus for preparing a perforated panel for reticulation to a film adhesive. The method includes supporting the perforated panel. The method also includes adhering the film adhesive to the perforated panel without initiating a cure of the film adhesive. The method applies a vacuum to the film adhesive. Next the method will move the perforated panel at a predetermined speed through a reticulation unit. Next the method will soften the film adhesive and finally remove the film adhesive from the perforations by an airflow. The method is generally used for creating acoustic sheet panels for use in many industries.

This is a divisional of application Ser. No. 10/255,910, filed Sep. 26,2002, now U.S. Pat. No. 6,736,181.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to applying an adhesive to apanel, and more particularly, relates to applying a film adhesive to anacoustic face sheet for use in the aerospace industry.

2. Description of Related Art

Methods for applying an adhesive to a core of an acoustic face sheet foruse in aerospace or other industries, that require sound dampening, havebeen known for many years. These prior art core reticulation systems, asthey are known, have the film adhesive directly reticulated onto thecore of the acoustic panels. After reticulation the core is connected toa surface of the acoustic panel and aligned such that the holes orperforations of the acoustic panel align with the holes of the core. Thecore reticulation system generally has the film adhesive softened andmaintained at the softened state on the core by radiant heaters. Afterthe film adhesive is softened on the core it is passed over an air knifein order to remove the film adhesive from the holes of the corematerial.

Generally, the core has a honeycomb type shape and it is desired to havethe adhesive only on the top portions of the core itself and not withinthe orifices of the honeycomb core. In the prior art system ofreticulation the core, after having the film adhesive softened, willpass through a reticulator on a wire rack that slides on rails withinthe reticulator. Then an air knife will direct compressed air fromunderneath the core and at a distance of approximately one foot awayfrom the core. This will allow for the adhesive to be blown from aroundthe top of each cell of the honeycomb cell structure thus in theoryleaving the cell passages clear and adhesive free. The end product ofthe prior art core reticulation system is a core that would include filmadhesive around the edge of the core cells. However, many of the priorart systems, due to the size difference of the core cells and ply holes,would have the ply holes blocked during bonding which also would lead toadhesive run off which clogs even more of the perforations in theacoustic panels. The acoustic panels generally work by absorbing soundwithin the perforations or orifices of the acoustic face sheet. If anyof these holes are blocked or the adhesive runs off, which can causeblockage in even more holes, then the acoustic absorption ability of theacoustic face sheet is sharply reduced.

The prior art method of core reticulation encounters numerous problemsduring the reticulation of the core. First, the air knife used to cut orremove the skin adhesive from the core is driven by compressed air thatgenerally includes contaminants that mix with and degrade the adhesivethat is left on the ends of the core cells of the core reticulationsystem. These contaminants will reduce the adhesive force between thecore and outer panels or skins of an acoustic face sheet. Any separationof the outer panel of the acoustic member from the core will degrade thenoise absorption characteristics of the panel, reduce structuralintegrity and also create extraneous noise due to any vibration betweenthe loosely connected core and outer panels. Another problem associatedwith the prior art core reticulation method is that the air surroundingthe film adhesive is capable of cooling which leads to tears in the filmadhesive on the edge of the core cells. These tears will reduce theeffectiveness of the film adhesive, when the film adhesive is alignedwith and secured to the panel. Furthermore, if the air cools enough andthe air knife is not run at an appropriate pressure the film adhesivewill not be removed from over the opening of the cell in the honeycombcore structure thus blocking the acoustic absorption for that cell andreducing the overall effectiveness of the acoustic absorption of theacoustic sheet. The prior art core reticulation method also has problemsdeveloping and having uniform fillets along the edge of the honeycombcells. Furthermore, if the wrong angle is used for the air knife, withrelation to the core, a venturi can develop within each individual celland the fillet would not be properly formed on top of the cell thuscausing a reduction in the acoustic absorption capability of any suchdamaged cell.

The prior art core reticulation method also generally leaves defectswithin the core reticulation system of greater then twenty percent.Manufacturers want the acoustic sheet panels to be less then ten percentdegraded due to unopened or blocked core cells in the honeycomb core ofan acoustic sheet. The noise attenuation of the acoustic face sheets isparamount in the design of modem day aerospace vehicles. The moreblocked cells in the honeycomb core the less the noise absorptionpotential for the acoustic panel. These acoustic panels line cockpits,bodies, wings and even containment walls inside an engine, thusreduction of noise is key to the effectiveness of such products.

Therefore, there is a need in the art for a new reticulation method thatwill directly adhere the film adhesive to the panel instead of the edgeof the honeycomb core. There is also a need in the art for areticulation method that will reduce the amount of contamination andpartially block or blocked cells in the acoustic face sheet core cells.Furthermore, there is a need in the art for a low cost method formanufacturing and building acoustic face sheet panels.

SUMMARY OF THE INVENTION

One object of the present invention is to provide an improved method ofreticulation.

Another object of the present invention is to provide a new method andapparatus for panel and film adhesive reticulation.

Yet a further object of the present invention is to provide a method ofpanel reticulation that will maintain a constant temperature and promotesoftening of a film adhesive before passing over an air flow.

Still a further object of the present invention is to provide a methodof creating panel and film adhesive reticulation on a variety ofcontoured parts.

Still another object of the present invention is to provide a method ofpanel reticulation that reduces the contamination of the film adhesiveand any tearing of the film adhesive.

Still a further object of the present invention is to provide a methodof panel and film adhesive reticulation without any orifice blockagesbetween the core and holes in the perforated panel.

To achieve the fore going objects, a method for panel and film adhesivereticulation includes the steps of supporting the panel with a contouredsurface. The method also includes applying an amount of pressure to thefilm adhesive and panel by a vacuum mechanism. The method also includesheating the film adhesive with a low grade heat until initial adhesionof the film adhesive to the panel without curing of the film adhesive.Next the method will move the panel, with initial film adhesion, througha reticulation unit which includes a contoured head and a shroud. Thepanel will be in contact with the contoured head. The method alsoincludes softening the film adhesive with heat such that the heat iscontained within the shroud. The reticulation method will then dry,filter and heat an air flow prior to entering a nozzle located withinthe contoured head. The method will then move the film adhesive from theperforations of the panel with a predetermined rate of air flow.

One advantage of the present invention is that the method of panel andfilm adhesive reticulation connects the film adhesive directly to thepanel and not the core.

A further advantage of the present invention is that the film adhesiveis softened and maintained in such a state before passing over an airflow.

Another advantage of the present invention is that the panel and filmadhesive reticulation apparatus includes a shroud which provides a morestable environment than radiant heaters during the reticulation process.

Still a further advantage of the present invention is that theperforated panel is moved over a contour surface plate that can bechanged to accommodate part shape.

Still another advantage of the present invention is that the airflow iscleaned, dried and heated prior to being used to remove film adhesive.

Still another advantage of the present invention is that the airflow isdirected onto the panel at close proximity.

Still a further advantage of the present invention is that the airflowwill not produce turbulence because of the close proximity of theairflow to the panel.

Still another advantage of the present invention is that the airflowwill have no cooling affect on the film adhesive.

Still another advantage of the present invention is the reduction incost and manufacturing time of an acoustic face sheet.

Still another advantage of the present invention is that an acousticface sheet that has a significant improvement in acoustic performance,i.e. sound absorption and sound dampening.

Other objects, features and advantages of the present invention willbecome apparent from the subsequent description and the appended claims,taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a top view of a prior art honeycomb core.

FIG. 2 shows a close up of the prior art honeycomb core cells withadhesive and without film adhesive thereon.

FIG. 3 shows a side view of prior art honeycomb core cells with a filmadhesive fillet at the top end thereof.

FIG. 4 shows a schematic of the reticulation unit according to thepresent invention.

FIG. 5 shows a perspective view of the adhesion unit according to thepresent invention.

FIG. 6 shows a schematic view of the adhesion unit according to thepresent invention.

FIG. 7 shows a perspective view of the reticulation unit according tothe present invention.

FIG. 8 shows a cross section view of a panel after the reticulationmethod according to the present invention has been performed.

FIG. 9 shows a top view of a perforated panel after the reticulationmethod according to the present invention has been performed.

DESCRIPTION OF THE EMBODIMENT(S)

Referring to the drawings, a method and apparatus for panel and filmadhesive reticulation according to the present invention is shown. Thepanel and film adhesive reticulation method and apparatus is generallyused to manufacture acoustic aerospace face sheets or panels for uses inaerospace vehicles. The use in such aerospace vehicles could be anythingfrom containment walls for engines to skins for the body and wings ofsuch vehicles. The acoustic face sheet generally is made of graphite orfiberglass, however it should be noted that other materials could alsobe used such as composite materials, plastics, or metals depending onthe design and weight requirements of the aircraft. The key to acousticface panels is the noise attenuation. The panels have a honeycomb corecell that is used to dampen noise and/or absorb acoustic waves. Thepanels will help to dampen any noise being heard by passengers andpilots of airplanes or other aerospace vehicles. If the core cells inthe acoustic panel are blocked or partially blocked by film adhesive orcontaminants connected to film adhesive then the noise absorptioncapability and noise dampening capability of the acoustic panels will begreatly reduced thus, creating more extraneous noise for the operator orpassengers of airplanes and the like.

The present invention will allow for reticulating a film adhesive 14onto a perforated panel 10 which will yield an end product which hasfilm adhesive 14 covering the panel surfaces without covering, partiallyor completely, the perforation or orifices 12 in the perforated panel10. This will allow for the orifices 12 of the perforated panel 10 toalign precisely with the cells in the honeycomb core thus providing theacoustic absorption and sound dampening capabilities for the acousticpanels. The end product of an acoustic panel includes a solid panel onone side thereof with the honeycomb core glued to that surface and thenthe perforated panel 10, having the film adhesive reticulation methodperformed on it, secured to the opposite end of the honeycomb core cellvia a curing of the film adhesive between the core and panel 10. Wheninstalled in an engine containment wall or a skin of an airplane, theperforated panel 10 will have the orifices 12 placed towards the insidecomponents of the engine such as the fan or turbine blades to effect thesound absorption capabilities of the perforated acoustic panel system.

FIGS. 1 through 3 show a prior art method of core reticulation. Corereticulation occurs on a honeycomb core 16 that includes a plurality ofcells 18 therein. The honeycomb core 16 is then placed between a ply anda solid panel on the opposite end to form an acoustic face sheet. Corereticulation has the film adhesive 20 reticulated directly on to thecore 16 edge. The film adhesive 20 is softened and maintained at a softstate on the core 16 by radiant heaters. The core 16 is then passedthrough a unit on a wire rack which slides on rails over an air knifewhich is used to remove the film adhesive 20 from the cells 16 such thatit only rests and is fixed on the outer edges of the core cells 18. Inthe prior art systems the air knife directs compressed air from beneaththe core 16 at approximately one foot in distance. This air knife willblow air through the adhesive and in theory leave the adhesive onlylocated around the top of each cell, with the cell passages free fromand clear from film adhesive 20. However, in practice this does notalways occur. The film adhesive 20 is supposed to only adhere around theedge of the core cells 18. However, in the prior art method due to thesize difference of core cells 18 and ply holes many of the ply holes areblocked during bonding. Furthermore, with the film adhesive 20 attachedto the edge of the core cells 18 adhesive run off is more likely thusincreasing the chance of clogging a cell 18 with the adhesive prior toand after being secured to the ply panel. FIG. 3 shows a side view ofthe prior art core cells and the film adhesive 20 having a filletlocated at the top edge of each core cell 18 after the reticulationprocess has been applied. FIG. 2 shows a close up of the honeycomb corecell 16 with one side having the film adhesive 20 reticulated thereonand the other side having no adhesive thereon.

FIGS. 4 through 9 show the apparatus and method for panel and filmadhesive reticulation according to the present invention. The methodwill allow a panel 10 to be reticulated for bonding with a film adhesive14. The apparatus needed to perform the panel and film adhesivereticulation according to the present invention includes an adhesionunit 22 and a reticulation unit 24.

The adhesion unit 22 as shown in FIGS. 5 and 6 includes a table or base26 and a cover 28. The cover 28 is rotatable about an axis on one sideof the table 26 such that the cover 28 opens and closes relative to thetable 26. The cover 28 has a radiant heat source 30 located on an insidesurface thereof. In one embodiment the radiant heat source 30 is aplurality of electric bulbs. The electric bulbs will give off apredetermined amount of heat, in one embodiment approximately 120°Fahrenheit of low grade heat is necessary. However, it should be notedthat any where between a range of 70° to 220° Fahrenheit heat may beused for the adhesion unit 22. It should also be noted that otherradiant heat sources can also be used such as heated air, thermalblankets, etc. The temperature and dwell times used in this operationwill need to be customized for different film adhesive systems. Acousticsystems, outside the scope of the aerospace industry, may require verydifferent parameters. Therefore, the apparatus and equipment of thepresent invention has variable controls to accommodate such changes.These other heat sources can be used depending if they are appropriatefor the part configuration or the variables of the film adhesive systemused in the present invention. Thus, the heat source 30 of the adhesionunit 22 radiates heat down towards the perforated panel 10 which issupported on the table 26 of the adhesion unit 22. The perforated panel10 is supported by a contoured surface or mandrel 32 that mimics theshape of the panel 10 which will be used in the aerospace vehicle. Theuse of the contoured mandrel 32 will allow for the perforated panel 10to have complete support during the adhesion unit operation thuspreventing any distortion through the initial adhesion process of thepanel and film adhesive reticulation method.

The adhesion unit 22 also includes a vacuum system through a surface ofthe table 26. The adhesion unit 22 includes a vacuum bag 34 that isconnected at one side of the table 26 and is capable of being lifted upfrom the other side of the table 26. In one embodiment the vacuum bag 34will be a rubber pad but other materials may be used for the vacuum bagsuch as but not limited to plastic, composites, metal, etc. The vacuumthat is applied to the table 26 is created by at least one orifice 36through the table 26 thus allowing for the vacuum bag 34 to becompressed towards the surface of the table 26 after the vacuum isapplied through the orifice 36. The vacuum bag 34 will allow for a mildpressure i.e. approximately 10 to 20 psi, to be applied to the filmadhesive 14 and perforated panel 10 during the adhesion unit stage ofthe method. It should be noted that the pressure is a mild pressure andthat too low or too high of a pressure will adversely affect the initialadhesion of the film adhesive 14 to the perforated panel 10. It shouldbe noted that the adhesion unit 22 is used to create a level of adhesionbetween the perforated panel 10 and the film adhesive 14 withoutinitiating a cure of the film adhesive 14. It should also be noted thatvariables within the adhesion unit 22 are capable of adjustment thusproviding for different adhesive configurations. A variety of panelconfigurations can also be accommodated by switching the contouredsurface mandrel 32 to one that matches a new part being reticulated.

As shown in FIG. 6 the contoured mandrel 32 is placed directly on theouter surface of the table 26. Then a perforated panel 10 is placeddirectly over the contoured mandrel 32. The mandrel 32 will mimic theexact shape of the perforated panel 10 thus providing support throughoutthe entire adhesion unit process. Next a film adhesive 14 layer isplaced directly on top of the perforated panel 10. It should be notedthat the perforated panel 10 includes a plurality of orifices 12therethough. There the vacuum bag 34 is placed over the film adhesive 14and a vacuum is applied via the table 26 such that the vacuum bag 34 iscompressed downward towards the table 26 thus compressing the filmadhesive 14 into the perforated panel 10 with a mild pressure. The cover28 of the table is then closed and the radiant heat source 30 is turnedon such that heat and mild pressure are applied to the film adhesive 14and perforated panel 10. The heat and pressure are left on forapproximately 30 (thirty) seconds, that will allow for an initialadhesion between the film adhesive 14 and perforated panel 10 withoutinitiating a cure of the film adhesive 14. This dwell time will varywith different film adhesive systems. Generally, the film adhesive 14will begin to display bubbles throughout when an initial adhesion hasbeen reached. It should be noted that 30 seconds is an approximate timefor the adhesion unit step of the panel reticulation method. It shouldbe noted that anywhere from a few seconds up to a number of minutescould be used for the initial adhesion between the film adhesive 14 andthe perforated panel 10.

After the film adhesive 14 is temporarily adhered to the perforatedpanel 10 in the adhesive unit 22 steps two of the reticulation system isbegun. As shown in FIGS. 4 and 7 step two includes putting theperforated panel 10, having the film adhesive 14 partially adheredthereto, into a reticulation unit 40. The reticulation unit 40 includesa table 42. The table 42 has a cast or formed rubber contoured head 44located on a top surface of the table 42. The cast or formed rubbercontoured head 44 is interchangeable and is contoured such that it willmatch the surface of the perforated panel 10. The contour head or plate44 in one embodiment is made of a rubber material. However, it should benoted any other castable or formable plastic, composite or metalmaterial maybe used for the cast contoured head or plate 44. It shouldalso be noted that the contoured head or plate 44 is interchangeablesuch that the plate can be removed from the table 42 and a new contourhead 44 replaced therein thus allowing for changing of perforated panel10 parts for the reticulation process. Through a center point of thecontoured head is located an air nozzle 46 which will direct an airflow48 up through the contoured head 44. The contour head 44, which ismatched to a particular panel, will help provide a more evendistribution of air flow pressure to the panel being processed.

Located directly above and adjacent to the contoured head 44 is a shroud50. The shroud 50 is preferably made of a metal material. However, itshould be noted that any other type of ceramic, plastic or compositematerial capable of containing heat made also be used for the shroud 50.The shroud 50 also contains a window therein which allows for viewing ofthe reticulation process. The shroud 50 acts as a containment for heatwhich will keep the film adhesive 14 warm prior to and during thereticulation process. The shroud 50 provides a greenhouse affect thatwill keep the air heated properly during the entire reticulationprocess. The shroud 50 generally has a cup like shaped cross-section. Itshould be noted that the shroud 50 is capable of movement relative tothe contoured head 44, such that in one embodiment approximately a oneinch gap will occur between the ends of the shroud 50 and the filmadhesive side of the perforated panel 10. It should be noted that thegap could be anywhere from a couple of inches up to a couple of feetdepending on the size of the perforated panel 10 being reticulated.

The reticulation unit 40 also includes, as shown in FIGS. 4 and 7, atleast one filter and drier mechanism 52. The filter and drier 52 willfilter and dry the air that is used to create the airflow 48 for thereticulation process. The filtered and dried air 48 will be movedthrough a series of tubing 54 to a heating unit 56 by a blower 58. Theheating unit 56 will heat the air 48 to a predetermined temperaturewhich in one embodiment is approximately 165° to 175° Fahrenheit.However, it should be noted that any range of temperatures from 60°Fahrenheit up to 400° Fahrenheit maybe used depending on the needs ofthe airflow 48 for the reticulation process. The heating unit 56 islocated below the bottom surface of the table 42. The heating unit 56 isthen directly connected to either the bottom of the table 42 or thebottom of the contoured head 44 which includes the nozzle 46 through acenter portion thereof. The nozzle 46 will ensure that the airflow 48has a predetermined width and diameter size. The heated air flow 48 willbe directed into a chamber 62 located immediately before the nozzleorifice 46. The air chamber 62 will equalize heat and air flow pressuredistribution across the length of the nozzle 46. The airflow 48 will becapable of different pressures due to variables in the blower 58. Acontrol box 60 is also located on or near the table 42 and provideselectronic controls for the heat and airflow rate. Therefore, the heatcan be programmed and the airflow rate also programmed by the operatorof the reticulation unit 40.

In operation the panel and film adhesive reticulation method will, afterthe film adhesive 14 has been initially applied to the perforated panel10 in the adhesion unit 22, be completed in the reticulation unit 40directly after the adhesion unit 22 step or soon thereafter. Theperforated panel 10 will be moved in a predetermined direction throughthe reticulation unit 40. The speed at which the perforated panel 10 ismoved through the reticulation unit 40 can vary depending on the amountof reticulation needed and the size and materials of the parts. Amaterial transfer system may be utilized to control the rate of movementof a part through the reticulation system. However, in one embodimentthe reticulation unit 40 has each row of orifices 12 in the perforatedpanel 10 over the air knife or airflow 48 for approximately one secondhowever any other amount of time over the airflow or air knife 48 isalso contemplated depending on the design requirements and airflow 48needed to allow for complete reticulation of the orifices 12 in theperforated panel 10. The nozzle 46 will apply a dried, filtered andheated airflow 48 through the orifices or perforations 12 of theperforated panel 10 from the side of the panel 10 that does not have thefilm adhesive 14 thereon. It should further be noted that the perforatedpanel 10 is in contact with or in close proximity and is directlyparallel to the nozzle 46. This will allow the airflow 48 to be parallelto the panel orifices 12 at all times thus allowing for a parallelairflow 48 through the orifices 12 of the perforated panel 10. The rateor pressure of airflow 48, the amount of heat and the rate at which thepanels 10 move through the unit 40 are all capable of adjustment thusthese variables can be changed to accommodate different requirements fordifferent panels in the adhesive system being reticulated. The contouredhead 44 is also capable of being designed to different perforated panelshapes and is thus interchangeable as different perforated panels areworked into the reticulation unit 40.

The shroud 50 is located at a predetermined distance from the panel 10surface side which includes the film adhesive 14, in order to containthe heat and promote a softening of the film adhesive 14 prior tomovement through the airflow 48. This will allow the film adhesive 14 tobe in a soft easily removable state when it passes over the airflow 48,thus allowing for complete removal of all film adhesive 14 from theorifices 12 of the perforated panel 10. The perforated panel 10 and filmadhesive 14 during the time they are under the shroud 50 are maintainedat a constant temperature. The shroud 50 creates a more stableenvironment than radiant heaters used in prior art core reticulationsystems. The shroud 50 promotes a greenhouse effect that willre-circulate the heated air to ensure a uniform temperature of the filmadhesive 14 under the shroud 50. The perforated panel 10 is pushedthrough manually over the contoured head 44 such that curvature of theperforated panel 10 will not be a constrain of the reticulation unit 40.It should also be noted that it is contemplated that an automatic methodof moving the perforated panel 10 through the reticulation unit 10 canalso be used. The use of the airflow 48, having clean dry heated air,directly onto the perforated panel 10 from a very close or directtouching proximity will ensure that no contaminants are present in theairflow 48. Furthermore, the close proximity of the airflow 48 to thebottom of the panel 10 will ensure that any part angularity will notproduce turbulence within the orifices 12 which will allow for completereticulation and opening of the orifices 12 in the perforated panel 10.If the airflow 48 entered the orifices 12 at an angle thereto, a venturimight be developed within the orifice 12 thus keeping the film adhesive14 from completely clearing away from the orifice 12, and allowing aportion of film adhesive 14 to remain in the orifice 12. This wouldreduce the acoustic absorption rate of the perforated panel 10.Furthermore, having the airflow 48 directly in contact with theperforated panel 10 will ensure no cooling effect of the airflow 48before it reaches the film adhesive 14 thus removing the possibility oftearing or ripping of the film adhesive 14 prior to proper removal fromthe orifice 12 of the perforated panel 10. The adhesion of the filmadhesive 14 to the perforated panel 10 instead of the core will allowfor a uniform cure between both parts without any orifice 12 blockagebetween the perforated panel 10 and the core. This will result insignificant improvement of acoustic performance thus increasing sounddampening.

FIG. 9 shows a top view of a perforated panel 10 after the panelreticulation process had been completed. FIG. 8 shows a cross-section ofsuch panel 10. The end product panel will exhibit film adhesive 14uniformly adhered to the perforated panel 10. It should be noted thatthe film adhesive 14 is uncured at this stage. The perforated panel 10will have no orifice 12 blockage thus allowing for complete acousticdampening effect when the perforated panel 10 is finally attached to thehoneycomb cell core.

After the panel and film adhesive reticulation process is complete theperforated panel 10 will be aligned with a honeycomb cell core that isalready been attached to a like shaped backing material. The perforatedpanel 10 will be secured to the honeycomb core cell such that curing ofthe film adhesive 14 occurs and a secure connection is created betweenthe perforated panel 10 and honeycomb core. The honeycomb cells in thecore will align with the orifices 12 of the perforated panel 10 thusallowing for the acoustic dampening effects to be included in theacoustic perforated panel. Sound waves will enter through the orifices12 of the perforated panels 10 and into the honeycomb core structure andbe dissipated therein thus dampening any noise being released from within the containment of the perforated panel acoustic sheet system. Itshould be noted that the invention has been described for aerospaceparts but the panel reticulation system can be used in any otherindustry where a film adhesive 14 is to be initially set to a panel 10of any type prior to final curing of the adhesive to a separate part.

The present invention has been described in an illustrative manner. Itis to be understood that the terminology which has been used is intendedto be in the nature of words of description rather than of limitation.

Many modifications and variations of the present invention are possiblein light of the above teachings. Therefore, within the scope of theappended claims, the present invention maybe practiced otherwise then asspecifically described.

1. A method of reticulating a film adhesive onto a perforated panel,said method including the steps of: supporting the perforated panel;adhering the film adhesive to the perforated panel without initiating acure of the film adhesive; applying a vacuum to the film adhesive;softening of the film adhesive; moving the perforated panel at apredetermined speed through a reticulation unit, said reticulation unithaving a contour head with a nozzle therein, said perforated panel incontact with said contour head; and removing the film adhesive from theperforations by an airflow.
 2. The method of claim 1 wherein said stepof supporting prevents distortion of the panel.
 3. The method of claim 1wherein said step of applying a vacuum to said firm adhesive creates apressure of approximately 10 to 20 psi between the film adhesive and thepanel thus allowing for initial adhesion.
 4. The method of claim 1further including the step of placing said airflow directly on theperforated panel.
 5. The method of claim 1 further including the step offiltering said airflow.
 6. The method of claim 1 further including thestep of heating said airflow.
 7. The method of claim 1 wherein said stepof softening includes the step of containing heat near the film adhesiveby a shroud and creating a greenhouse effect by said shroud.
 8. Themethod of claim 1 wherein said step of removing includes the step ofcontrolling the rate of airflow such that the heated film adhesive iscut away from the perforations and forms a reticulated pattern.
 9. Themethod of claim 1 wherein said step of softening occurs prior tomovement of the panel over said airflow.
 10. The method of claim 1wherein said step of adhering further includes the step of heating thefilm adhesive.
 11. The method of claim 10 further including the step ofusing a radiant heat source for said heating at a temperature between70° and 200° F. for a predetermined amount of time.
 12. A method forpanel and film adhesive reticulation, said method including the stepsof: using a contoured surface to support eh panel; applying pressure tothe film adhesive and panel by a vacuum mechanism; heating the filmadhesive until initial adhering of the film adhesive without curing;moving the panel, with initial film adhesion, through a reticulationunit, said reticulation unit including a contour head having a nozzletherein for directing an airflow and said reticulation unit having ashroud, the panel in contact with said contour head; softening the filmadhesive with heat, said heat is contained within said shroud; dryingsaid airflow; filtering said airflow; heating said airflow prior toentering said nozzle; and removing said film adhesive from theperforations in the panel with a predetermined rate of said airflow.